Question

I’m trying to create a script/application which accepts command line arguments when run. Of course, this is a day-to-day thing, but seeing as this is the first time I’m doing it, I’m looking for some guidance. Let’s say my script can take these kinds of command line arguments:

script -a -p /path/to/pipe -l mail.Error -m [e-mail]
script -a -l mail.Error -m [e-mail] -p /path/to/pipe

and so on....

Due to the flexible nature of command line scripts, the arguments you can pass to it can some in a variety of orders and could be missing/have invalid arguments. Now, I know this can be solved by being very strict about how the arguments must show up (first -a, then -p with a path, then -l with a log facility/priority and finally -m with a valid email) and by testing all possible occurrences of them.

But there has to be a better way. This is incredibly inefficient (to me) and I was wondering if there was a better way of doing things. I want to remain as flexible as possible and just make things work instead of focusing on strict usage.

Answer 1

I use Getopt::Long for arguments.

Untested example:

use Getopt::Long;
## set defaults
my $path   = '/tmp';
my $log = 'm.Error';
my $email = '[e-mail]';
my $a = 0;
my $result = GetOptions ("path=s"  => \$path,
                         "log=s"   => \$log,
                         "a"       => \$a,
                         "email=s" => \$email);
## both script -a -p /path/to/pipe -l mail.Error -m [e-mail]
## and script -a -l mail.Error -m [e-mail] -p /path/to/pipe
## should work now